Tools, especially hand tools, may be considered as expedients to enhance the natural functions of one's arms, hands and fingers. For example, long tongs and fine needles provide access into areas where arms and fingers are too short or too large; long handle shears and wrenches provide increased strength through mechanical advantage; and tweezer tools provide increased dexterity in handling delicate articles. Such tools are particularly effective when they are operably simulative of one's natural movements because one can instinctively remember how to operate them.
The electronics industry is typical of a field where articles to be handled are small, light in weight and delicate in nature. For example, lids on chip carriers are only about 6-10 mm square and weigh about 0.15 to 0.25 grams. In another example, a paper-thin chip of silicon may contain a complex integrated circuit and may be only about 1 mm square. It is inappropriate to handle such lids or chips with conventional tweezers for many reasons. It is difficult to get under a lid or a chip for pickup and grasping a chip by squeezing upon both faces can be destructive of the integrated circuit. Moreover, the chips often have a magnetic material applied to a major surface so an array of chips can be handled on a magnetic carrier and the attraction thereto complicates a pickup procedure.
A popular method of handling the above articles, and especially chips, is by operation of a vacuum powered probe. The probe has a holding end with a vacuum port which communicates with a slender tube connected to a vacuum source. There is a valve which is finger operated to apply vacuum to a chip on pickup and to relieve the vacuum on placement. Problems with vacuum handling are high first cost and high maintenance cost of a pervasive vacuum service to a production line. Another problem accompanies the slender vacuum tube which drags about and can be disruptive of a work area.
In view of the foregoing, it is desirable to provide new and improved expedients to handle magnetic articles. A tool is desired to pick and place small, light-weight magnetic articles which are delicate in nature. Such tool should handle a flat article by non-destructively contacting only one surface of the flat article. In a tweezer tool embodiment, maximal dexterity should be provided by operably simulating the natural movements of human hands and fingers.